Val-Matic Tilted Disc Check Valve User Manual

Manual No.

TDCV-OM1-4

Val-Matic®

Tilted Disc® Check Valve

Operation, Maintenance and

Installation Manual

INTRODUCTION...............................................	1
RECEIVING AND STORAGE ...........................	1
DESCRIPTION OF OPERATION......................	1
INSTALLATION ................................................	2
VALVE CONSTRUCTION.................................	3
MAINTENANCE................................................	4
TROUBLESHOOTING ......................................	4
DISASSEMBLY.................................................	5
REASSEMBLY..................................................	5
OPTIONAL BMOD ............................................	8
OPTIONAL TMOD ............................................	11
OPTIONAL BYPASS.........................................	15
PARTS AND SERVICE.....................................	15
WARRANTY .....................................................	16

VAL-MATIC® VALVE AND MANUFACTURING CORP.

905 Riverside Dr.

Phone [phone]

www.valmatic.com

●Elmhurst, IL 60126

●Fax [phone]

TILTED DISC® CHECK VALVE

OPERATION, MAINTENANCE AND INSTALLATION

INTRODUCTION

This manual will provide you with the information to properly install and maintain the check valve to ensure a long service life. The Tilted Disc Check Valve is ruggedly constructed with aluminum-bronze or stainless steel trim to give years of trouble free operation. The valve should be installed in water pipelines three diameters downstream of pumps to prevent reverse flow.

CAUTION

For valves with Top Mounted Dashpots, DO NOT paint exposed surfaces of the connecting rod or the cylinder piston rod or damage will result to the hydraulic seals.

The valve is designed to open after pump start and allow water to flow through the pipeline or water main while creating a minimal amount of headloss. A top or bottom mounted oil dashpot may be included to control the opening and closing of the valve. The valve size, cold working pressure, and model number are stamped on the nameplate for reference.

This valve is not intended for fluids containing suspended solids such as wastewater. For wastewater and other high turbidity applications, use

Val-Matic Series 500 Swing-Flex Check Valve.

CAUTION

The Tilted Disc Check Valve is not intended for use with sewage or fuel service.

RECEIVING AND STORAGE

Inspect valves upon receipt for damage in shipment. Unload all valves carefully to the ground without dropping. When lifting, the valve should be lifted with straps or bolts in the flange holes. The valve should never be lifted by the dashpot assembly.

The valves should remain crated, clean and dry until installed to prevent weather related damage. For long-term storage greater than six months, the valves should be stored indoors or the ends of the valve should be sealed with plastic wrap to prevent weather related damage.

FIGURE 1. Tilted Disc Check Valve

DESCRIPTION OF OPERATION

The Tilted Disc Check Valve consists of two body sections bolted together at a central 55-degree diagonal flange assembly, forming a single valve body. The inlet body section contains a seat ring positioned and captured by the diagonal flanges. The outlet section contains two eccentrically located pivot pins from which a disc, containing a beveled disc ring, pivots 40 degrees from the closed to the fully open position.

The location of the eccentric pivot trunnions allows the seating surface of the disc ring to rotate away from the seating surface of the seat ring, without contact, when the valve opens. Conversely, during closing the seating surface of the disc ring moves into the seating surface of the seat ring without contact, until final sealing contact is made. A small amount of clearance exists between the pivot pin and the pivot pin bushing when the disc ring makes full contact with the seat ring to ensure a tight seal.

The flow area throughout the valve equals or exceeds the flow area of the pipe, thus minimizing the head loss through the valve.

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DESCRIPTION OF OPERATION (cont’d)

Upon pump start-up, the forward flow of water will start to rotate the disc about the pivot pins until the disc rotates through a 40-degree arc and contacts the integral body stops. The partially balanced disc assists in opening the disc and stabilizes the disc in low-flow cases where the valve remains partially open.

On pump shutdown, the forward velocity of the water starts to diminish, until the disc is no longer held against the body stops and the partially balanced disc will move to the closed position. When the forward velocity reaches zero, the disc will have moved to the closed position and the reversal of flow is checked. The 40-degree travel of the disc and the partially balanced disc reduces the potential for check valve slam and water hammer normally associated with conventional swing check valves.

However, ideal hydraulic conditions are not always predictable and the potential for water hammer can still exist. Applications with a potential for valve slam include high-head pumping, multiple high service pumps, and the use of hydro-pneumatic surge tanks. If the reversal of flow occurs before the disc has a chance to fully close, it will be driven to the closed position by the rapid flow reversal.

For these rapid flow reversal conditions, a bottom mounted hydraulic dashpot can be fitted in the bottom inspection port, provided that sufficient clearance is provided for installation. The bottom mounted oil dashpot will control the last 10 degrees of disc travel between 1 and 5 seconds. A top mounted dashpot can also be used. A top mounted oil dashpot performs the same function as a bottom dashpot and in addition, independently controls the full open and closing strokes between 5 and 30 seconds to prevent line surges.

INSTALLATION

The installation of the valve is important for its proper operation. The Tilted Disc Check Valve can only be used for horizontal flow or vertical flow-up applications.

CAUTION

For horizontal flow applications, the valve must be installed with both of the eccentric pivot pin trunnions located above the horizontal centerline of the valve and they must be level to the horizontal plane of the valve.

Each valve is provided with a flow arrow integrally cast on the valve body and a flow arrow printed on the metal label attached to the valve. These flow arrows must point in the direction the water will flow, when the system is operating. ANSI Class 125 and Class 250 Cast Iron valves are furnished with flat

faced flanges and should be mated with flat faced companion flanges. The valve and adjacent piping must be supported and aligned to prevent cantilevered stress being transferred to the valve’s flanges when installing the flange bolts or studs. For raised face applications, a ductile iron valve body should be specified.

CAUTION

The valve must be mated with flat-faced flanges or damage may result. The use of excessive bolt torque can damage the valve.

When mating the check valve with butterfly isolation valves, the clearance between the butterfly disc and the fully open check valve stem must be checked. A spacer pipe is sometimes needed. See the valve arrangement drawing for disc clearance dimensions.

FLANGED ENDS: The flange should be mated with flat-faced pipe flanges equipped with resilient gaskets. When ring gaskets are used, the bolt material shall be ASTM A307 Grade B or SAE Grade 2 Carbon Steel. Higher strength bolts should only be used with full-face gaskets.

INSTALLATION: Lower valve into the pipeline using slings or chains around the valve body. Eye bolts or bars can also be used in the bolt holes. Lubricate the flange bolts and insert them around the flange. Lightly turn bolts until gaps are eliminated. The tightening of the bolts should then be done in graduated steps using the cross-over tightening method. Recommended lubricated torques for use with resilient gaskets (75 durometer) is given in Table 1. Do not exceed bolt rating or crush gasket more than 50 percent of its thickness.

125# FLANGE DATA			250# FLANGE DATA
Valve	Bolt	Bolt	Valve	Bolt	Bolt
Size	Dia.	Torque	Size	Dia.	Torque
(in)	(in)	(ft-lbs)	(in)	(in)	(ft-lbs)
4	5/8	30-90	4	3/4	50-150
6	3/4	30-90	6	3/4	70-150
8	3/4	40-120	8	7/8	90-200
10	7/8	45-150	10	1	110-300
12	7/8	65-200	12	1 1/8	160-450
14	1	80-250	14	1 1/8	140-450
16	1	90-300	16	1 1/4	180-600
18	1 1/8	100-350	18	1 1/4	190-600
20	1 1/8	120-450	20	1 1/4	220-600
24	1 1/4	150-500	24	1 1/2	350-900
30	1 1/4	180-600	30	1 3/4	500-1500
36	1 1/2	250-750	36	2	700-2000
42	1 1/2	300-900	42	2	800-2500
48	1 1/2	400-900	48	2	900-1800
54	1 3/4	400-1200	-	-	-

TABLE 1. Flange Bolt Torques

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VALVE CONSTRUCTION

The standard Tilted Disc Check valve is ruggedly constructed of cast iron. See the specific Materials List submitted for the order if other than standard iron construction. The internal metal components are aluminum bronze or stainless steel. The pivot pins (4) are fixed in the body (1) and support the disc (3). Grease fittings (23) are provided to allow regular lubrication of the pivot pin. The general details of construction are illustrated in Figure 2.

The body is flanged to connect to a pipe flange. The body consists of a pivot body half (1) and a seat pivot half (2). The seat (11) is held in place by the

two body halves. Top and bottom inspection hole covers (13) are provided for servicing the valves and to allow installation of dashpots. Do not remove the inspection covers while the pipeline is under pressure or the cover may release pressure suddenly.

WARNING

Removal of inspection covers without draining the pipeline and valve may cause serious injury.

Figure 2. Basic Valve Construction

Part No. Part Name		Material	Part No. Part Name		Material
1	Pivot Body Half	Cast or Ductile Iron	16	Pivot Pin Cover	Cast Iron
2	Seat Body Half	Cast or Ductile Iron	17*	Pivot Pin Cover Gasket	Non-Asbestos
3	Disc	Cast or Ductile Iron	18	Pivot Pin Cover Bolt	Alloy Steel
4*	Pivot Pin	Alum. Brz.	19	Indicator Pin (>6”)	Stainless Steel
5*	Pivot Pin Bushing (>12”)	Alum. Brz.	20	Indicator Shaft Assy (>6”)	Stainless Steel
6*	Body Seal	Buna-N	21	Indicator Washer (>6”)	Stainless Steel
7	Body Flange Bolt	Alloy Steel	22	Indicator Pointer (>6”)	Carbon Steel
8	Disc Ring (>12”)	Alum. Brz.	23*	Grease Fitting	Stainless Steel
9	Ring Seal (>12”)	Buna-N	24*	Indicator O-rings (>6”)	Buna-N
10	Seat Ring	Alum. Brz.	25	Lock Washer (>6”)	Stainless Steel
11	Seat Ring Seal	Buna-N	26	Indicator Jam Nut (>6”)	Stainless Steel
12	Ring Ret. Screw (>12”)	Stainless Steel	27	Locating Pins	Plated Steel
13	Inspection Cover (>6”)	Cast Iron
14	Cover Bolt (>6”)	Alloy Steel
15*	Gasket (>6”)	Non-Asbestos	*Recommended Spare Part

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MAINTENANCE

The operation of the valve can be seen by observing the movement of the indicator pointer on the side of the valve (6” and larger sizes). The valve should move about 40 degrees from the closed to the fully open position. It is normal for the valve to not fully open in cases where the fluid velocity is less than 8 ft/sec or a Top Mounted Oil Dashpot is installed.

Dashpot assemblies require regular maintenance. See the dashpot section in this manual.

LUBRICATION: The Tilted Disc Check Valve is provided with grease fittings (23) located on the pivot pin covers. The valve’s pivot trunnions must be lubricated at least monthly or as conditions dictate with a waterproof, FDA or ANSI/NSF 61 approved grease such as Lubriko #CW-606 (Master Lubricants Co., Philadelphia, Pa). Using a cartridge grease gun, pump grease into each grease fitting using 8 full strokes of the grease gun lever.

INSPECTION: Periodic inspection for leakage can be performed by placing a listening device or an ear on the valve while it is closed and the line is under pressure. If leakage is heard, close the isolation valve and drain the valve connection, and inspect the seating surfaces for wear or mineral deposits. Clean or repair trim as needed.

WARNING

Removal of inspection covers without draining the pipeline and valve may cause serious injury.

The inspection hole covers can be removed from the valve to facilitate internal inspection of the valve. A hoist or jacking mechanism should be used to lift the disc to inspect the seating surfaces. If replacement of the disc, pivot pin bushings, disc ring, or seat ring is required, the valve must first be removed from the line.

TROUBLESHOOTING

Several problems and solutions are presented below to assist you in trouble shooting the valve assembly in an efficient manner.

TROUBLESHOOTING BASIC VALVE: The valve opens automatically without the need of a power source to allow forward flow. The valve may not open to the full open position depending on fluid velocity but it will always open far enough to pass the flow with a minimal headloss. The valve will automatically close to prevent reverse flow through the pump. The valve has metal seats and a moderate bang during closing is normal.

1.Leakage at Valve Inspection Covers (13): Retighten bolts evenly or replace non-asbestos sheet gasket.

2.Leakage at Grease fitting: Inject grease or replace grease fitting (23).

3.Leakage at Mating Flanges: Re-tighten bolts using the cross-over method or replace mating flange gasket. Flange gaskets are typically 70 durometer resilient material. Check alignment of mating pipe.

4.Valve Leaks when Closed: Flush debris from seat by cycling valve. Verify that valve is subject to a minimum differential pressure of at least 10 psi when closed and the isolation butterfly or gate valve is open. If leakage persists, inspect interior of valve. Clean seating surfaces. When used with a power operated control valve, there may not be sufficient reverse flow to seat the valve. These types of installations require a power outage for proper valve seating so that the pump is tripped while the control valve is open.

5.Valve Fails to Open: Check pressure differential across disc; upstream pressure must be greater than downstream pressure. Verify that the suction and discharge shutoff valves are open and there is no line blockage. Drain pipe on both sides of the valve, remove inspection cover (13), and inspect disc ring (8) and seat ring (10) for damage or wedged debris.

6.Noisy Operation: Flow noise is normal. Loud flow noise similar to hammering may be cavitation from dropping high pressures across valve; review flow velocity through valve and pump application.

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DISASSEMBLY OF BASIC VALVE

The valve should be removed from the pipeline for disassembly. All work on the valve should be performed by a skilled mechanic with proper tools. Refer to Figure 2.

WARNING

The line must be drained before removing the valve or pressure may be released causing injury.

1.Lay valve on flat surface or bench with the inlet flange face down.

2.Using a flat-nosed punch, drive out the two locating pins (27).

3.Remove the indicator jam nut (26), lockwasher (25), pointer (22), pivot pin cover bolts (18) and covers (16).

4.Remove the pivot pins (4). The end of the pin is tapped for insertion of a 9/16”-18 or 3/4”-16 threaded rod.

5.Attach a hoist to the outer flange of the valve to support the weight of the outlet body section of the valve and remove the diagonal flange bolts

(7).

6.Using the hoist, raise the outlet body section of the valve. If the valve sections are joined tightly by the gasket, lift the valve 1/8” and hammer the inlet body section down with a soft-blow hammer or block of wood. Once the body sections are separated, raise the outlet section to clear the disc pivot trunnions and place the outlet section on a wooden skid.

7.Remove the pivot pin bushings (5) from the disc pivot trunnions on 12” and larger valves. They may be set in place with sealant so apply heat to the disc trunnions with a propane torch to soften the Loctite if necessary.

8.Thread an eye bolt into one of the threaded holes in the disc’s rectangular pad. Using a nylon sling through the disc trunnions and eye bolt, lift the disc straight up while maintaining its 55 degree tilt.

9.Place the disc on a wooden skid and using the nylon sling through just the eye bolt, turn the disc over with the disc ring (8) facing up.

All parts can now be easily inspected for wear or damage and replacement parts can be ordered as needed. If replacing the seat (10) or disc ring (8), it is recommended that they be replaced as a set. The pivot pins (4) should fit tightly in the body, but there

should be ample clearance (at least 1/32”) between the pins (4) and the bushings (5).

REASSEMBLY OF BASIC VALVE

All parts must be clean and gasket surfaces should be cleaned with a stiff wire brush in the direction of the serrations or machine marks. Worn parts, gaskets, and seals should be replaced during reassembly.

1. Place the seat body half (2), with the inlet flange face down on a wooden skid.

2. Install a lightly lubricated seat ring seal (11) in the register of the seat body half.

3. Install the seat ring (10) with the serrated surface toward the seal, into the register of the body seat half.

4. With the disc on a wooden skid, and the disc ring register up, place a lightly lubricated disc ring seal (9) onto the disc register.

5. Assemble the disc ring with the serrated face toward the seal.

6. Place a small amount of Loctite thread locking compound on each of the retaining screws (12) and thread them into the tapped holes in the disc. Tighten them initially hand tight and then using the cross-over tightening method, torque each screw in graduated steps, according to the following chart.

Valve Sizes	Torque
12” to 14”	13 ft-lbs
16” to 24”	20 ft-lbs
30”	28 ft-lbs
36” and larger	40 ft-lbs

7. Thread in eye bolt into one of the threaded holes in the disc’s rectangular pad. Insert a nylon sling through the eye bolt and attach the loops of the sling to the hook of a hoist. Carefully turn over the disc, using the hoist, making sure that the beveled seating surface of the disc ring does not make contact with metal or hard surfaces.

8. Install the pivot pin bushings into the disc pivot trunnions with Loctite 680.

9. Remove the nylon sling from the eye bolt and place it through the disc’s pivot trunnions bores and attach the loops of the sling to the hoist. Attach a short chain from the hoist’s hook to the eyebolt and adjust the length of the chain to keep the disc at a 55 degree angle when housing the disc.

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